<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./css/index.css" />
    <title>记事本</title>
  </head>
  <body>
    <!-- 主体区域 -->
    <section id="app">
      <!-- 输入框 -->
      <header class="header">
        <h1>小黑记事本</h1>
        <input
          placeholder="请输入任务"
          class="new-todo"
          v-model.trim="addContent"
          @keyup.enter="add"
        />
        <button class="add" @click="add">添加任务</button>
      </header>
      <!-- 列表区域 -->
      <section class="main">
        <ul class="todo-list">
          <li class="todo" v-for="(item,index) in list" :key="item.id">
            <div class="view">
              <span class="index">{{ index+1 }}</span>
              <label>{{ item.name }}</label>
              <button @click="del(item.id)" class="destroy"></button>
            </div>
          </li>
        </ul>
      </section>
      <!-- 统计和清空 -->
      <footer class="footer" v-if="list.length > 0">
        <!-- 统计 -->
        <span class="todo-count"
          >合 计:<strong> {{ list.length }} </strong></span
        >
        <!-- 清空 -->
        <button class="clear-completed" @click="list = []">清空任务</button>
      </footer>
    </section>

    <!-- 底部 -->
    <script src="../../../vue.js"></script>
    <script>
      const app = new Vue({
        el: "#app",
        data: {
          list: [
            { id: 1, name: "跑步" },
            { id: 2, name: "跳绳" },
            { id: 3, name: "篮球" },
            { id: 4, name: "音乐" },
          ],
          addContent: "",
        },
        methods: {
          del(id) {
            this.list = this.list.filter((item) => item.id != id);
          },
          add() {
            if (this.addContent === "") {
              alert("内容不能为空");
              return;
            }
            this.list.unshift({
              id: +new Date(),
              name: this.addContent,
            });
            this.addContent = "";
          },
        },
      });
    </script>
  </body>
</html>
